Evaluation of Reverse Tone Mapping Through
Varying Exposure Conditions |
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SIGGRAPH Asia 2009. ACM Transactions on Graphics 28, 5 (December 2009) | |||||
Abstract: | |||||
Most
existing image content has low dynamic range (LDR), which necessitates
effective methods to display such legacy content on high dynamic range
(HDR) devices. Reverse tone mapping operators (rTMOs) aim to take LDR
content as input and adjust the contrast intelligently to yield output
that recreates the HDR experience. In this paper we show that current
rTMO approaches fall short when the input image is not exposed
properly. More specifically, we report a series of perceptual
experiments using a Brightside HDR display and show that, while
existing rTMOs perform well for under-exposed input data, the perceived
quality degrades substantially with over-exposure, to the extent that
in some cases subjects prefer the LDR originals to images that have
been treated with rTMOs. We show that, in these cases, a simple rTMO
based on gamma expansion avoids the errors introduced by other methods,
and propose a method to automatically set a suitable gamma value for
each image, based on the image key and empirical data. We validate the
results both by means of perceptual experiments and using a recent
image quality metric, and show that this approach enhances visible
details without causing artifacts in incorrectlyexposed regions.
Additionally, we perform another set of experiments which suggest that
spatial artifacts introduced by rTMOs are more disturbing than
inaccuracies in the expanded intensities. Together, these findings
suggest that when the quality of the input data is unknown, reverse
tone mapping should be handled with simple,non-aggressive methods to achieve the desired effect.
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Direct Links: | |||||
[Paper]
[Slides (18MB)] New! Related publication: Multilinear Regression for Gamma Expansion of Overexposed Content [Paper] Related publication: Selective Reverse Tone Mapping [Paper] Related publication: Understanding Exposure for Reverse Tone Mapping [Paper] |
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BibTeX: | |||||
@ARTICLE{Masia09,
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@techreport{Masia11,
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@INPROCEEDINGS{Masia10,
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@INPROCEEDINGS{Martin08,
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